In fact the WRT45G is and isn't certified...because there are three versions of the product:-

Ver 1 has the Broadcom WiFi card as a plug in Mini-PCI card on the motherboard and is certified for 802.11b ONLY

Ver 1.1 has the WiFi built into the motherboard and is certified for 802.11b ONLY

Ver 2 has the WiFi built onto the motherboard, has an upgraded processor and more memory and is certified for 802.11b and 802.11g

However you can't buy a version 2 in the UK at the moment (and no-one knows when you will be able to!!). The WRT54G has also been extensively hacked and there is a Linux firmware set available for it that supports substantially more functionality.

Paul